The Sea Ghost (1931)

(aka U67) The Sea Ghost is a 1931 American Pre-Code film directed by William Nigh and starring Alan Hale, Clarence Wilson, Claud Allister and Laura La Plante. The film was re-titled U 67 for its American reissue, stating in the foreword that “some of the scenes in this film show authentic exploits of the U 67 under actual wartime conditions”.
Greg Winters, a disgraced World War 1 naval officer, is the Captain of a salvage-ship in New Orleans in 1925. He crosses paths with Evelyn Inchcape, a man-hating owner of a cabaret and the heir to a fortune, and Karl Ludwig, a former German submarine commander, searching for salvation on the docks of New Orleans.